The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
One way of joining two pieces of wood is with pocket holes and screws. This type of joint has been around for centuries. A screw hole is drilled in one board at an angle and a “pocket” is formed for the head of the screw to fit into. The pockets used to be formed by chisels, and the hole used to be drilled with a brace and a bit. Today, machines can form both a pocket and a through hole much more quickly. This attachment method is illustrated in FIG. 29. In FIG. 29, the Part A is fastened to the Part B by a screw 2 which is inserted through a pre-drilled pocket 4 that is formed in Part A. It is important for the strength of the joint for the screw 2 to exit Part A at approximately halfway through the thickness of the material.
The present disclosure provides a jig that is used with a power hand drill that automatically sets itself up to make a pocket hole. This makes it very easy and fast for the user to make this joint. The user can also concentrate his thinking on the finished project instead of concentrating on having to set up the tool. In fact, the user does not even have to know that the thickness of the wood he is using; the jig adapts automatically to the wood's thickness.
It is also important for the pocket to be drilled to the correct height. If the height is too small, the screw will stick through the surface of Part B. If the height is too big, the joint will not be as strong as it should be. The correct pocket height will be different for different thickness of wood and different screw lengths.
There are several pocket hole jigs on the market today that are used with a drill. These use drill guide bushings that are used to guide a stepped drill. The drill guide bushing is at an appropriate angle for drilling the pocket hole. A stop collar on the drill bit controls the pocket height. Some jigs have the guide bushing slidably attached to a base. Because of the angle of the guide bushing, raising the guide bushing assembly moves the exit location of the screw in Part A further away from the surface of the wood that is touching the guide bushing assembly. The user needs to know how far up to slide the guide bushing assembly for the thickness of wood that he is using. The user then needs to adjust the clamp pad for the thickness of wood. This is a trial and error method where the user adjusts the clamp stop, tries to clamp the wood and tightens or loosens the clamp stop accordingly. This is repeated until the appropriate clamping force is achieved. The user also needs to know the appropriate location the stop collar needs to be set on the drill bit that corresponds with the thickness of wood being used, and the user needs to set the stop collar accordingly. Once the hole is drilled, the user needs to look on a chart to determine the correct screw length to use that corresponds with the thickness of wood being used. Not only does the jig of the present disclosure automatically adjust for different width wood pieces, the jig is also provided with a gauge that points to the correct screw length for the wood thickness.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.